Most virtual environments include more space than can be viewed from a single focal point. Therefore, a 3D world is only as useful as a user's ability to move around and interact with information within that world. Users must be provided with the ability to navigate through the environment in order to obtain different views to investigate various scenes and objects within the virtual surroundings. The most common techniques of navigating through a 3D virtual world are computer mouse or joystick driven techniques. Forward or backward movement of a computer mouse or joystick provides the user with the illusion of moving a virtual body or camera forward or backward through the virtual environment. Left or right movement turns the body or camera left or right in the virtual environment. The virtual body or camera changes in position or orientation within the 3D graphical workspace to give the user a sensation of moving within the 3D graphical space. The problem is that if an object that the user desires to reach is a long distance from the location of the virtual body or camera, it takes a long time for the user to get to the object unless a built in acceleration mechanism is provided. The problem with built in acceleration mechanisms, is that the user has the tendency to overshoot the object and then must backtrack to the location of the object.
Numerous techniques have been employed to try to maximize the utility of display space to view existing information within the 3D environment. For example, in some virtual environment applications, the user is given the ability to zoom in and out and work at multiple scales for virtually expanding the viewing space. Mechanisms have been provided to allow a user to navigate through a space by modifying a search area in each view, or where the principle means for navigating is by employing a zooming feature in a user graphical interface. Other systems have been employed that provide a user simultaneous overlaying of both global and local views. Scaling techniques and transporting techniques have been developed to allow a user to move quickly to different locations in an environment. Typically, these systems require a user to work within or between two different unconstrained coordinate systems. Information visualization techniques are another mechanism for expanding the navigable space by distorting the views of the world. These techniques are sometimes disorienting and place additional cognitive load on the user to mentally re-map the spatial relations.
One particular technique referred to as “a point of interest technique” has proved relatively successful in providing a user with a mechanism to navigate easily through a 3D virtual world. The point of interest technique allows a user to focus on an object and to move toward that object automatically. System users can have arbitrary positions and orientations in each workspace and techniques are provided for rapidly controlled and targeted three dimensional movement by the user in the workspaces, such as the technique disclosed in U.S. Pat. No. 5,276,785 to Mackinlay et al., entitled “Moving Viewpoint with Respect to a Target in a Three Dimensional Workspace.” The viewpoint of the user (e.g., a virtual camera) can approach the point of interest (e.g., an object within the environment) asymptotically, with both radial and lateral motion. When the user requests viewpoint motion toward the point of interest, the system can provide animated motion so that the object constancy is preserved.
The problem with the point of interest technique and other information visualization techniques for navigating in a 3D environment is that the object must be in the user's field of view for the user to navigate to the object. Additionally, the user is presented with a predetermined forward face and vector normal to the face upon navigating to the object. A user may move around and inspect the object by simultaneously holding down both a forward and backward key. This has proven to be difficult and awkward for users when inspecting the object. Furthermore, the user is not able to navigate with a single motion of the input device.
Accordingly, there is an unmet need in the art for a system and method for providing improved navigation techniques to facilitate user interactions with a given visual metaphor in order to achieve a higher level of ease of use for a user navigating through a virtual world.